﻿using System;
using System.Collections;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using MySql.Data;
using MySql.Data.MySqlClient;

namespace Domain.Security
{ 
        /// <summary>   
        /// SqlServer数据访问帮助类   
        /// </summary>   
        public sealed class SqlHelper
        {
            #region 私有构造函数和方法

            private SqlHelper() { }

            /// <summary>   
            /// 将MySqlParameter参数数组(参数值)分配给MySqlCommand命令.   
            /// 这个方法将给任何一个参数分配DBNull.Value;   
            /// 该操作将阻止默认值的使用.   
            /// </summary>   
            /// <param name="command">命令名</param>   
            /// <param name="commandParameters">SqlParameters数组</param>   
            private static void AttachParameters(MySqlCommand command, MySqlParameter[] commandParameters)
            {
                if (command == null) throw new ArgumentNullException("command");
                if (commandParameters != null)
                {
                    foreach (MySqlParameter p in commandParameters)
                    {
                        if (p != null)
                        {
                            // 检查未分配值的输出参数,将其分配以DBNull.Value.   
                            if ((p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input) &&
                                (p.Value == null))
                            {
                                p.Value = DBNull.Value;
                            }
                            command.Parameters.Add(p);
                        }
                    }
                }
            }

            /// <summary>   
            /// 将DataRow类型的列值分配到MySqlParameter参数数组.   
            /// </summary>   
            /// <param name="commandParameters">要分配值的MySqlParameter参数数组</param>   
            /// <param name="dataRow">将要分配给存储过程参数的DataRow</param>   
            private static void AssignParameterValues(MySqlParameter[] commandParameters, DataRow dataRow)
            {
                if ((commandParameters == null) || (dataRow == null))
                {
                    return;
                }

                int i = 0;
                // 设置参数值   
                foreach (MySqlParameter commandParameter in commandParameters)
                {
                    // 创建参数名称,如果不存在,只抛出一个异常.   
                    if (commandParameter.ParameterName == null ||
                        commandParameter.ParameterName.Length <= 1)
                        throw new Exception(
                            string.Format("请提供参数{0}一个有效的名称{1}.", i, commandParameter.ParameterName));
                    // 从dataRow的表中获取为参数数组中数组名称的列的索引.   
                    // 如果存在和参数名称相同的列,则将列值赋给当前名称的参数.   
                    if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
                        commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
                    i++;
                }
            }

            /// <summary>   
            /// 将一个对象数组分配给MySqlParameter参数数组.   
            /// </summary>   
            /// <param name="commandParameters">要分配值的MySqlParameter参数数组</param>   
            /// <param name="parameterValues">将要分配给存储过程参数的对象数组</param>   
            private static void AssignParameterValues(MySqlParameter[] commandParameters, object[] parameterValues)
            {
                if ((commandParameters == null) || (parameterValues == null))
                {
                    return;
                }

                // 确保对象数组个数与参数个数匹配,如果不匹配,抛出一个异常.   
                if (commandParameters.Length != parameterValues.Length)
                {
                    throw new ArgumentException("参数值个数与参数不匹配.");
                }

                // 给参数赋值   
                for (int i = 0, j = commandParameters.Length; i < j; i++)
                {
                    // If the current array value derives from IDbDataParameter, then assign its Value property   
                    if (parameterValues[i] is IDbDataParameter)
                    {
                        IDbDataParameter paramInstance = (IDbDataParameter)parameterValues[i];
                        if (paramInstance.Value == null)
                        {
                            commandParameters[i].Value = DBNull.Value;
                        }
                        else
                        {
                            commandParameters[i].Value = paramInstance.Value;
                        }
                    }
                    else if (parameterValues[i] == null)
                    {
                        commandParameters[i].Value = DBNull.Value;
                    }
                    else
                    {
                        commandParameters[i].Value = parameterValues[i];
                    }
                }
            }

            /// <summary>   
            /// 预处理用户提供的命令,数据库连接/事务/命令类型/参数   
            /// </summary>   
            /// <param name="command">要处理的MySqlCommand</param>   
            /// <param name="connection">数据库连接</param>   
            /// <param name="transaction">一个有效的事务或者是null值</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>   
            /// <param name="commandText">存储过程名或都T-SQL命令文本</param>   
            /// <param name="commandParameters">和命令相关联的MySqlParameter参数数组,如果没有参数为'null'</param>   
            /// <param name="mustCloseConnection"><c>true</c> 如果连接是打开的,则为true,其它情况下为false.</param>   
            private static void PrepareCommand(MySqlCommand command, MySqlConnection connection, MySqlTransaction transaction, CommandType commandType, string commandText, MySqlParameter[] commandParameters, out bool mustCloseConnection)
            {
                if (command == null) throw new ArgumentNullException("command");
                if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

                // If the provided connection is not open, we will open it   
                if (connection.State != ConnectionState.Open)
                {
                    mustCloseConnection = true;
                    connection.Open();
                }
                else
                {
                    mustCloseConnection = false;
                }

                // 给命令分配一个数据库连接.   
                command.Connection = connection;

                // 设置命令文本(存储过程名或SQL语句)   
                command.CommandText = commandText;

                // 分配事务   
                if (transaction != null)
                {
                    if (transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                    command.Transaction = transaction;
                }

                // 设置命令类型.   
                command.CommandType = commandType;

                // 分配命令参数   
                if (commandParameters != null)
                {
                    AttachParameters(command, commandParameters);
                }
                return;
            }

            #endregion 私有构造函数和方法结束

            #region 数据库连接
            /// <summary>   
            /// 一个有效的数据库连接字符串   
            /// </summary>   
            /// <returns></returns>   
            public static string GetConnSting()
            {
                return ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString;
            }
            /// <summary>   
            /// 一个有效的数据库连接对象   
            /// </summary>   
            /// <returns></returns>   
            public static MySqlConnection GetConnection()
            {
                MySqlConnection Connection = new MySqlConnection(SqlHelper.GetConnSting());
                return Connection;
            }
            #endregion

            #region ExecuteNonQuery命令

            /// <summary>   
            /// 执行指定连接字符串,类型的MySqlCommand.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>   
            /// <param name="commandText">存储过程名称或SQL语句</param>   
            /// <returns>返回命令影响的行数</returns>   
            public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
            {
                return ExecuteNonQuery(connectionString, commandType, commandText, (MySqlParameter[])null);
            }

        /// <summary>   
        /// 执行指定连接字符串,类型的MySqlCommand.   
        /// </summary>   
        /// <remarks>   
        /// 示例:    
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");   
        /// </remarks>   
        /// <param name="commandText">存储过程名称或SQL语句</param>   
        /// <returns>返回命令影响的行数</returns>   
        public static int ExecuteNonQuery(string commandText)
        {
            return ExecuteNonQuery(GetConnection(), CommandType.Text, commandText, (MySqlParameter[])null);
        }

        /// <summary>   
        /// 执行指定连接字符串,类型的MySqlCommand.如果没有提供参数,不返回结果.   
        /// </summary>   
        /// <remarks>   
        /// 示例:    
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter("@prodid", 24));   
        /// </remarks>   
        /// <param name="connectionString">一个有效的数据库连接字符串</param>   
        /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>   
        /// <param name="commandText">存储过程名称或SQL语句</param>   
        /// <param name="commandParameters">MySqlParameter参数数组</param>   
        /// <returns>返回命令影响的行数</returns>   
        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

                using (MySqlConnection connection = new MySqlConnection(connectionString))
                {
                    connection.Open();

                    return ExecuteNonQuery(connection, commandType, commandText, commandParameters);
                }
            }

            /// <summary>   
            /// 执行指定连接字符串的存储过程,将对象数组的值赋给存储过程参数,   
            /// 此方法需要在参数缓存方法中探索参数并生成参数.   
            /// </summary>   
            /// <remarks>   
            /// 这个方法没有提供访问输出参数和返回值.   
            /// 示例:    
            ///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串/param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="parameterValues">分配到存储过程输入参数的对象数组</param>   
            /// <returns>返回受影响的行数</returns>   
            public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果存在参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从探索存储过程参数(加载到缓存)并分配给存储过程参数数组.   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 给存储过程参数赋值   
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数情况下   
                    return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <returns>返回影响的行数</returns>   
            public static int ExecuteNonQuery(MySqlConnection connection, CommandType commandType, string commandText)
            {
                return ExecuteNonQuery(connection, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>   
            /// <param name="commandText">T存储过程名称或T-SQL语句</param>   
            /// <param name="commandParameters">SqlParamter参数数组</param>   
            /// <returns>返回影响的行数</returns>   
            public static int ExecuteNonQuery(MySqlConnection connection, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (connection == null) throw new ArgumentNullException("connection");

                // 创建MySqlCommand命令,并进行预处理   
                MySqlCommand cmd = new MySqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, connection, (MySqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

                // Finally, execute the command   
                int retval = cmd.ExecuteNonQuery();

                // 清除参数,以便再次使用.   
                cmd.Parameters.Clear();
                if (mustCloseConnection)
                    connection.Close();
                return retval;
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,将对象数组的值赋给存储过程参数.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值   
            /// 示例:    
            ///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回影响的行数</returns>   
            public static int ExecuteNonQuery(MySqlConnection connection, string spName, params object[] parameterValues)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果有参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程分配参数值   
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行带事务的MySqlCommand.   
            /// </summary>   
            /// <remarks>   
            /// 示例.:    
            ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");   
            /// </remarks>   
            /// <param name="transaction">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <returns>返回影响的行数/returns>   
            public static int ExecuteNonQuery(MySqlTransaction transaction, CommandType commandType, string commandText)
            {
                return ExecuteNonQuery(transaction, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// 执行带事务的MySqlCommand(指定参数).   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="transaction">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="commandParameters">SqlParamter参数数组</param>   
            /// <returns>返回影响的行数</returns>   
            public static int ExecuteNonQuery(MySqlTransaction transaction, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

                // 预处理   
                MySqlCommand cmd = new MySqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行   
                int retval = cmd.ExecuteNonQuery();

                // 清除参数集,以便再次使用.   
                cmd.Parameters.Clear();
                return retval;
            }

            /// <summary>   
            /// 执行带事务的MySqlCommand(指定参数值).   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值   
            /// 示例:    
            ///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);   
            /// </remarks>   
            /// <param name="transaction">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回受影响的行数</returns>   
            public static int ExecuteNonQuery(MySqlTransaction transaction, string spName, params object[] parameterValues)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果有参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数赋值   
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法   
                    return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值   
                    return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteNonQuery方法结束

            #region ExecuteDataset方法

            /// <summary>   
            /// 执行指定数据库连接字符串的命令,返回DataSet.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <returns>返回一个包含结果集的DataSet</returns>   
            public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
            {
                return ExecuteDataset(connectionString, commandType, commandText, (MySqlParameter[])null);
            }

        /// <summary>   
        /// 执行指定数据库连接字符串的命令,返回DataSet.   
        /// </summary>   
        /// <remarks>   
        /// 示例:    
        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");   
        /// </remarks>   
        /// <param name="connectionString">一个有效的数据库连接字符串</param>   
        /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
        /// <param name="commandText">存储过程名称或T-SQL语句</param>   
        /// <returns>返回一个包含结果集的DataSet</returns>   
        public static DataSet ExecuteDataset(string commandText)
        {
            return ExecuteDataset(GetConnection(), CommandType.Text, commandText, (MySqlParameter[])null);
        }

        /// <summary>   
        /// 执行指定数据库连接字符串的命令,返回DataSet.   
        /// </summary>   
        /// <remarks>   
        /// 示例:   
        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new MySqlParameter("@prodid", 24));   
        /// </remarks>   
        /// <param name="connectionString">一个有效的数据库连接字符串</param>   
        /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
        /// <param name="commandText">存储过程名称或T-SQL语句</param>   
        /// <param name="commandParameters">SqlParamters参数数组</param>   
        /// <returns>返回一个包含结果集的DataSet</returns>   
        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

                // 创建并打开数据库连接对象,操作完成释放对象.   
                using (MySqlConnection connection = new MySqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法.   
                    return ExecuteDataset(connection, commandType, commandText, commandParameters);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接字符串的命令,直接提供参数值,返回DataSet.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值.   
            /// 示例:   
            ///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回一个包含结果集的DataSet</returns>   
            public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中检索存储过程参数   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 给存储过程参数分配值   
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,返回DataSet.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名或T-SQL语句</param>   
            /// <returns>返回一个包含结果集的DataSet</returns>   
            public static DataSet ExecuteDataset(MySqlConnection connection, CommandType commandType, string commandText)
            {
                return ExecuteDataset(connection, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,指定存储过程参数,返回DataSet.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名或T-SQL语句</param>   
            /// <param name="commandParameters">SqlParamter参数数组</param>   
            /// <returns>返回一个包含结果集的DataSet</returns>   
            public static DataSet ExecuteDataset(MySqlConnection connection, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (connection == null) throw new ArgumentNullException("connection");

                // 预处理   
                MySqlCommand cmd = new MySqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, connection, (MySqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);
                cmd.CommandTimeout = 60;
                // 创建MySqlDataAdapter和DataSet.   
                using (MySqlDataAdapter da = new MySqlDataAdapter(cmd))
                {
                    DataSet ds = new DataSet();

                    // 填充DataSet.   
                    da.Fill(ds);

                    cmd.Parameters.Clear();

                    if (mustCloseConnection)
                        connection.Close();
                    cmd.Dispose();
                    connection.Dispose();
                    return ds;
                }
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,指定参数值,返回DataSet.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输入参数和返回值.   
            /// 示例.:    
            ///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回一个包含结果集的DataSet</returns>   
            public static DataSet ExecuteDataset(MySqlConnection connection, string spName, params object[] parameterValues)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 比缓存中加载存储过程参数   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程参数分配值   
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定事务的命令,返回DataSet.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");   
            /// </remarks>   
            /// <param name="transaction">事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名或T-SQL语句</param>   
            /// <returns>返回一个包含结果集的DataSet</returns>   
            public static DataSet ExecuteDataset(MySqlTransaction transaction, CommandType commandType, string commandText)
            {
                return ExecuteDataset(transaction, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// 执行指定事务的命令,指定参数,返回DataSet.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="transaction">事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名或T-SQL语句</param>   
            /// <param name="commandParameters">SqlParamter参数数组</param>   
            /// <returns>返回一个包含结果集的DataSet</returns>   
            public static DataSet ExecuteDataset(MySqlTransaction transaction, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

                // 预处理   
                MySqlCommand cmd = new MySqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 创建 DataAdapter & DataSet   
                using (MySqlDataAdapter da = new MySqlDataAdapter(cmd))
                {
                    DataSet ds = new DataSet();
                    da.Fill(ds);
                    cmd.Parameters.Clear();
                    return ds;
                }
            }

            /// <summary>   
            /// 执行指定事务的命令,指定参数值,返回DataSet.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输入参数和返回值.   
            /// 示例.:    
            ///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);   
            /// </remarks>   
            /// <param name="transaction">事务</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回一个包含结果集的DataSet</returns>   
            public static DataSet ExecuteDataset(MySqlTransaction transaction, string spName, params object[] parameterValues)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数分配值   
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteDataset数据集命令结束

            #region ExecuteReader 数据阅读器

            /// <summary>   
            /// 枚举,标识数据库连接是由SqlHelper提供还是由调用者提供   
            /// </summary>   
            private enum SqlConnectionOwnership
            {
                /// <summary>由SqlHelper提供连接</summary>   
                Internal,
                /// <summary>由调用者提供连接</summary>   
                External
            }

            /// <summary>   
            /// 执行指定数据库连接对象的数据阅读器.   
            /// </summary>   
            /// <remarks>   
            /// 如果是SqlHelper打开连接,当连接关闭DataReader也将关闭.   
            /// 如果是调用都打开连接,DataReader由调用都管理.   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="transaction">一个有效的事务,或者为 'null'</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名或T-SQL语句</param>   
            /// <param name="commandParameters">SqlParameters参数数组,如果没有参数则为'null'</param>   
            /// <param name="connectionOwnership">标识数据库连接对象是由调用者提供还是由SqlHelper提供</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            private static MySqlDataReader ExecuteReader(MySqlConnection connection, MySqlTransaction transaction, CommandType commandType, string commandText, MySqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
            {
                if (connection == null) throw new ArgumentNullException("connection");

                bool mustCloseConnection = false;
                // 创建命令   
                MySqlCommand cmd = new MySqlCommand();
                try
                {
                    PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                    // 创建数据阅读器   
                    MySqlDataReader dataReader;

                    if (connectionOwnership == SqlConnectionOwnership.External)
                    {
                        dataReader = cmd.ExecuteReader();
                    }
                    else
                    {
                        dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                    }

                    // 清除参数,以便再次使用..   
                    // HACK: There is a problem here, the output parameter values are fletched   
                    // when the reader is closed, so if the parameters are detached from the command   
                    // then the SqlReader can磘 set its values.   
                    // When this happen, the parameters can磘 be used again in other command.   
                    bool canClear = true;
                    foreach (MySqlParameter commandParameter in cmd.Parameters)
                    {
                        if (commandParameter.Direction != ParameterDirection.Input)
                            canClear = false;
                    }

                    if (canClear)
                    {
                        cmd.Parameters.Clear();
                    }

                    return dataReader;
                }
                catch
                {
                    if (mustCloseConnection)
                        connection.Close();
                    throw;
                }
            }

            /// <summary>   
            /// 执行指定数据库连接字符串的数据阅读器.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  MySqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名或T-SQL语句</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
            {
                return ExecuteReader(connectionString, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// 执行指定数据库连接字符串的数据阅读器,指定参数.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  MySqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名或T-SQL语句</param>   
            /// <param name="commandParameters">SqlParamter参数数组(new MySqlParameter("@prodid", 24))</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                MySqlConnection connection = null;
                try
                {
                    connection = new MySqlConnection(connectionString);
                    connection.Open();

                    return ExecuteReader(connection, null, commandType, commandText, commandParameters, SqlConnectionOwnership.Internal);
                }
                catch
                {
                    // If we fail to return the SqlDatReader, we need to close the connection ourselves   
                    if (connection != null) connection.Close();
                    throw;
                }

            }

            /// <summary>   
            /// 执行指定数据库连接字符串的数据阅读器,指定参数值.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            /// 示例:    
            ///  MySqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接对象的数据阅读器.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  MySqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名或T-SQL语句</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(MySqlConnection connection, CommandType commandType, string commandText)
            {
                return ExecuteReader(connection, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  MySqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandParameters">SqlParamter参数数组</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(MySqlConnection connection, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                return ExecuteReader(connection, (MySqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
            }

            /// <summary>   
            /// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数值.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            /// 示例:    
            ///  MySqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">T存储过程名</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(MySqlConnection connection, string spName, params object[] parameterValues)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteReader(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  MySqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(MySqlTransaction transaction, CommandType commandType, string commandText)
            {
                return ExecuteReader(transaction, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///   MySqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(MySqlTransaction transaction, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

                return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
            }

            /// <summary>   
            /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            ///   
            /// 示例:    
            ///  MySqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReader(MySqlTransaction transaction, string spName, params object[] parameterValues)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果有参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值   
                    return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteReader数据阅读器

            #region ExecuteScalar 返回结果集中的第一行第一列

            /// <summary>   
            /// 执行指定数据库连接字符串的命令,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
            {
                // 执行参数为空的方法   
                return ExecuteScalar(connectionString, commandType, commandText, (MySqlParameter[])null);
            }

        /// <summary>   
        /// 执行指定数据库连接字符串的命令,返回结果集中的第一行第一列.   
        /// </summary>   
        /// <remarks>   
        /// 示例:    
        ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");   
        /// </remarks>    
        /// <param name="commandText">存储过程名称或T-SQL语句</param>   
        /// <returns>返回结果集中的第一行第一列</returns>   
        public static object ExecuteScalar(string commandText)
        {
            // 执行参数为空的方法   
            return ExecuteScalar(GetConnection(), CommandType.Text, commandText, (MySqlParameter[])null);
        }

        /// <summary>   
        /// 执行指定数据库连接字符串的命令,指定参数,返回结果集中的第一行第一列.   
        /// </summary>   
        /// <remarks>   
        /// 示例:    
        ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new MySqlParameter("@prodid", 24));   
        /// </remarks>   
        /// <param name="connectionString">一个有效的数据库连接字符串</param>   
        /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
        /// <param name="commandText">存储过程名称或T-SQL语句</param>   
        /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>   
        /// <returns>返回结果集中的第一行第一列</returns>   
        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                // 创建并打开数据库连接对象,操作完成释放对象.   
                using (MySqlConnection connection = new MySqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法.   
                    return ExecuteScalar(connection, commandType, commandText, commandParameters);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接字符串的命令,指定参数值,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            ///   
            /// 示例:    
            ///  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果有参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 给存储过程参数赋值   
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法   
                    return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值   
                    return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount");   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalar(MySqlConnection connection, CommandType commandType, string commandText)
            {
                // 执行参数为空的方法   
                return ExecuteScalar(connection, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,指定参数,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalar(MySqlConnection connection, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (connection == null) throw new ArgumentNullException("connection");

                // 创建MySqlCommand命令,并进行预处理   
                MySqlCommand cmd = new MySqlCommand();

                bool mustCloseConnection = false;
                PrepareCommand(cmd, connection, (MySqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行MySqlCommand命令,并返回结果.   
                object retval = cmd.ExecuteScalar();

                // 清除参数,以便再次使用.   
                cmd.Parameters.Clear();

                if (mustCloseConnection)
                    connection.Close();

                return retval;
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,指定参数值,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            ///   
            /// 示例:    
            ///  int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36);   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalar(MySqlConnection connection, string spName, params object[] parameterValues)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果有参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程参数赋值   
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法   
                    return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值   
                    return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定数据库事务的命令,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount");   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalar(MySqlTransaction transaction, CommandType commandType, string commandText)
            {
                // 执行参数为空的方法   
                return ExecuteScalar(transaction, commandType, commandText, (MySqlParameter[])null);
            }

            /// <summary>   
            /// 执行指定数据库事务的命令,指定参数,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalar(MySqlTransaction transaction, CommandType commandType, string commandText, params MySqlParameter[] commandParameters)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

                // 创建MySqlCommand命令,并进行预处理   
                MySqlCommand cmd = new MySqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行MySqlCommand命令,并返回结果.   
                object retval = cmd.ExecuteScalar();

                // 清除参数,以便再次使用.   
                cmd.Parameters.Clear();
                return retval;
            }

            /// <summary>   
            /// 执行指定数据库事务的命令,指定参数值,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            ///   
            /// 示例:    
            ///  int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36);   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalar(MySqlTransaction transaction, string spName, params object[] parameterValues)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果有参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // PPull the parameters for this stored procedure from the parameter cache ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数赋值   
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法   
                    return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值   
                    return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteScalar

            #region FillDataset 填充数据集
            /// <summary>   
            /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)</param>   
            public static void FillDataset(string connectionString, CommandType commandType, string commandText, DataSet dataSet, string[] tableNames)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (dataSet == null) throw new ArgumentNullException("dataSet");

                // 创建并打开数据库连接对象,操作完成释放对象.   
                using (MySqlConnection connection = new MySqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法.   
                    FillDataset(connection, commandType, commandText, dataSet, tableNames);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集.指定命令参数.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>   
            public static void FillDataset(string connectionString, CommandType commandType,
                string commandText, DataSet dataSet, string[] tableNames,
                params MySqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (dataSet == null) throw new ArgumentNullException("dataSet");
                // 创建并打开数据库连接对象,操作完成释放对象.   
                using (MySqlConnection connection = new MySqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法.   
                    FillDataset(connection, commandType, commandText, dataSet, tableNames, commandParameters);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集,指定存储过程参数值.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            ///   
            /// 示例:    
            ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, 24);   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>      
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            public static void FillDataset(string connectionString, string spName,
                DataSet dataSet, string[] tableNames,
                params object[] parameterValues)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (dataSet == null) throw new ArgumentNullException("dataSet");
                // 创建并打开数据库连接对象,操作完成释放对象.   
                using (MySqlConnection connection = new MySqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法.   
                    FillDataset(connection, spName, dataSet, tableNames, parameterValues);
                }
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,映射数据表并填充数据集.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>      
            public static void FillDataset(MySqlConnection connection, CommandType commandType,
                string commandText, DataSet dataSet, string[] tableNames)
            {
                FillDataset(connection, commandType, commandText, dataSet, tableNames, null);
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,映射数据表并填充数据集,指定参数.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>   
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>   
            public static void FillDataset(MySqlConnection connection, CommandType commandType,
                string commandText, DataSet dataSet, string[] tableNames,
                params MySqlParameter[] commandParameters)
            {
                FillDataset(connection, null, commandType, commandText, dataSet, tableNames, commandParameters);
            }

            /// <summary>   
            /// 执行指定数据库连接对象的命令,映射数据表并填充数据集,指定存储过程参数值.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            ///   
            /// 示例:    
            ///  FillDataset(conn, "GetOrders", ds, new string[] {"orders"}, 24, 36);   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            public static void FillDataset(MySqlConnection connection, string spName,
                DataSet dataSet, string[] tableNames,
                params object[] parameterValues)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (dataSet == null) throw new ArgumentNullException("dataSet");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果有参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程参数赋值   
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法   
                    FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
                }
                else
                {
                    // 没有参数值   
                    FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames);
                }
            }

            /// <summary>   
            /// 执行指定数据库事务的命令,映射数据表并填充数据集.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>   
            public static void FillDataset(MySqlTransaction transaction, CommandType commandType,
                string commandText,
                DataSet dataSet, string[] tableNames)
            {
                FillDataset(transaction, commandType, commandText, dataSet, tableNames, null);
            }

            /// <summary>   
            /// 执行指定数据库事务的命令,映射数据表并填充数据集,指定参数.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>   
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>   
            public static void FillDataset(MySqlTransaction transaction, CommandType commandType,
                string commandText, DataSet dataSet, string[] tableNames,
                params MySqlParameter[] commandParameters)
            {
                FillDataset(transaction.Connection, transaction, commandType, commandText, dataSet, tableNames, commandParameters);
            }

            /// <summary>   
            /// 执行指定数据库事务的命令,映射数据表并填充数据集,指定存储过程参数值.   
            /// </summary>   
            /// <remarks>   
            /// 此方法不提供访问存储过程输出参数和返回值参数.   
            ///   
            /// 示例:    
            ///  FillDataset(trans, "GetOrders", ds, new string[]{"orders"}, 24, 36);   
            /// </remarks>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>   
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param>   
            public static void FillDataset(MySqlTransaction transaction, string spName,
                DataSet dataSet, string[] tableNames,
                params object[] parameterValues)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (dataSet == null) throw new ArgumentNullException("dataSet");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果有参数值   
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数赋值   
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法   
                    FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
                }
                else
                {
                    // 没有参数值   
                    FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames);
                }
            }

            /// <summary>   
            /// [私有方法][内部调用]执行指定数据库连接对象/事务的命令,映射数据表并填充数据集,DataSet/TableNames/SqlParameters.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new MySqlParameter("@prodid", 24));   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="transaction">一个有效的连接事务</param>   
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>   
            /// <param name="commandText">存储过程名称或T-SQL语句</param>   
            /// <param name="dataSet">要填充结果集的DataSet实例</param>   
            /// <param name="tableNames">表映射的数据表数组   
            /// 用户定义的表名 (可有是实际的表名.)   
            /// </param>   
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param>   
            private static void FillDataset(MySqlConnection connection, MySqlTransaction transaction, CommandType commandType,
                string commandText, DataSet dataSet, string[] tableNames,
                params MySqlParameter[] commandParameters)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (dataSet == null) throw new ArgumentNullException("dataSet");

                // 创建MySqlCommand命令,并进行预处理   
                MySqlCommand command = new MySqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行命令   
                using (MySqlDataAdapter dataAdapter = new MySqlDataAdapter(command))
                {

                    // 追加表映射   
                    if (tableNames != null && tableNames.Length > 0)
                    {
                        string tableName = "Table";
                        for (int index = 0; index < tableNames.Length; index++)
                        {
                            if (tableNames[index] == null || tableNames[index].Length == 0) throw new ArgumentException("The tableNames parameter must contain a list of tables, a value was provided as null or empty string.", "tableNames");
                            dataAdapter.TableMappings.Add(tableName, tableNames[index]);
                            tableName += (index + 1).ToString();
                        }
                    }

                    // 填充数据集使用默认表名称   
                    dataAdapter.Fill(dataSet);

                    // 清除参数,以便再次使用.   
                    command.Parameters.Clear();
                }

                if (mustCloseConnection)
                    connection.Close();
            }
            #endregion

            #region UpdateDataset 更新数据集
            /// <summary>   
            /// 执行数据集更新到数据库,指定inserted, updated, or deleted命令.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order");   
            /// </remarks>   
            /// <param name="insertCommand">[追加记录]一个有效的T-SQL语句或存储过程</param>   
            /// <param name="deleteCommand">[删除记录]一个有效的T-SQL语句或存储过程</param>   
            /// <param name="updateCommand">[更新记录]一个有效的T-SQL语句或存储过程</param>   
            /// <param name="dataSet">要更新到数据库的DataSet</param>   
            /// <param name="tableName">要更新到数据库的DataTable</param>   
            public static void UpdateDataset(MySqlCommand insertCommand, MySqlCommand deleteCommand, MySqlCommand updateCommand, DataSet dataSet, string tableName)
            {
                if (insertCommand == null) throw new ArgumentNullException("insertCommand");
                if (deleteCommand == null) throw new ArgumentNullException("deleteCommand");
                if (updateCommand == null) throw new ArgumentNullException("updateCommand");
                if (tableName == null || tableName.Length == 0) throw new ArgumentNullException("tableName");

                // 创建MySqlDataAdapter,当操作完成后释放.   
                using (MySqlDataAdapter dataAdapter = new MySqlDataAdapter())
                {
                    // 设置数据适配器命令   
                    dataAdapter.UpdateCommand = updateCommand;
                    dataAdapter.InsertCommand = insertCommand;
                    dataAdapter.DeleteCommand = deleteCommand;

                    // 更新数据集改变到数据库   
                    dataAdapter.Update(dataSet, tableName);

                    // 提交所有改变到数据集.   
                    dataSet.AcceptChanges();
                }
            }
            #endregion

            #region CreateCommand 创建一条MySqlCommand命令
            /// <summary>   
            /// 创建MySqlCommand命令,指定数据库连接对象,存储过程名和参数.   
            /// </summary>   
            /// <remarks>   
            /// 示例:    
            ///  MySqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName");   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="sourceColumns">源表的列名称数组</param>   
            /// <returns>返回MySqlCommand命令</returns>   
            public static MySqlCommand CreateCommand(MySqlConnection connection, string spName, params string[] sourceColumns)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 创建命令   
                MySqlCommand cmd = new MySqlCommand(spName, connection);
                cmd.CommandType = CommandType.StoredProcedure;

                // 如果有参数值   
                if ((sourceColumns != null) && (sourceColumns.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 将源表的列到映射到DataSet命令中.   
                    for (int index = 0; index < sourceColumns.Length; index++)
                        commandParameters[index].SourceColumn = sourceColumns[index];

                    // Attach the discovered parameters to the MySqlCommand object   
                    AttachParameters(cmd, commandParameters);
                }

                return cmd;
            }
            #endregion

            #region ExecuteNonQueryTypedParams 类型化参数(DataRow)
            /// <summary>   
            /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回受影响的行数.   
            /// </summary>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回影响的行数</returns>   
            public static int ExecuteNonQueryTypedParams(String connectionString, String spName, DataRow dataRow)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回受影响的行数.   
            /// </summary>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回影响的行数</returns>   
            public static int ExecuteNonQueryTypedParams(MySqlConnection connection, String spName, DataRow dataRow)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定连接数据库事物的存储过程,使用DataRow做为参数值,返回受影响的行数.   
            /// </summary>   
            /// <param name="transaction">一个有效的连接事务 object</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回影响的行数</returns>   
            public static int ExecuteNonQueryTypedParams(MySqlTransaction transaction, String spName, DataRow dataRow)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // Sf the row has values, the store procedure parameters must be initialized   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
                }
            }
            #endregion

            #region ExecuteDatasetTypedParams 类型化参数(DataRow)
            /// <summary>   
            /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回DataSet.   
            /// </summary>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回一个包含结果集的DataSet.</returns>   
            public static DataSet ExecuteDatasetTypedParams(string connectionString, String spName, DataRow dataRow)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                //如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回DataSet.   
            /// </summary>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回一个包含结果集的DataSet.</returns>   
            ///   
            public static DataSet ExecuteDatasetTypedParams(MySqlConnection connection, String spName, DataRow dataRow)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回DataSet.   
            /// </summary>   
            /// <param name="transaction">一个有效的连接事务 object</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回一个包含结果集的DataSet.</returns>   
            public static DataSet ExecuteDatasetTypedParams(MySqlTransaction transaction, String spName, DataRow dataRow)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion

            #region ExecuteReaderTypedParams 类型化参数(DataRow)
            /// <summary>   
            /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回DataReader.   
            /// </summary>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReaderTypedParams(String connectionString, String spName, DataRow dataRow)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
                }
            }


            /// <summary>   
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回DataReader.   
            /// </summary>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReaderTypedParams(MySqlConnection connection, String spName, DataRow dataRow)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定连接数据库事物的存储过程,使用DataRow做为参数值,返回DataReader.   
            /// </summary>   
            /// <param name="transaction">一个有效的连接事务 object</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回包含结果集的MySqlDataReader</returns>   
            public static MySqlDataReader ExecuteReaderTypedParams(MySqlTransaction transaction, String spName, DataRow dataRow)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName);
                }
            }
            #endregion

            #region ExecuteScalarTypedParams 类型化参数(DataRow)
            /// <summary>   
            /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalarTypedParams(String connectionString, String spName, DataRow dataRow)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列.  
            /// </summary>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalarTypedParams(MySqlConnection connection, String spName, DataRow dataRow)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary>   
            /// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列.   
            /// </summary>   
            /// <param name="transaction">一个有效的连接事务 object</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="dataRow">使用DataRow作为参数值</param>   
            /// <returns>返回结果集中的第一行第一列</returns>   
            public static object ExecuteScalarTypedParams(MySqlTransaction transaction, String spName, DataRow dataRow)
            {
                if (transaction == null) throw new ArgumentNullException("transaction");
                if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                // 如果row有值,存储过程必须初始化.   
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()   
                    MySqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值   
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
                }
            }
            #endregion

        /// <summary>   
        /// SqlHelperParameterCache提供缓存存储过程参数,并能够在运行时从存储过程中探索参数.   
        /// </summary>   
        public sealed class SqlHelperParameterCache
        {
            #region 私有方法,字段,构造函数
            // 私有构造函数,妨止类被实例化.   
            private SqlHelperParameterCache() { }

            // 这个方法要注意   
            private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

            /// <summary>   
            /// 探索运行时的存储过程,返回MySqlParameter参数数组.   
            /// 初始化参数值为 DBNull.Value.   
            /// </summary>   
            /// <param name="connection">一个有效的数据库连接</param>   
            /// <param name="spName">存储过程名称</param>   
            /// <param name="includeReturnValueParameter">是否包含返回值参数</param>   
            /// <returns>返回MySqlParameter参数数组</returns>   
            private static MySqlParameter[] DiscoverSpParameterSet(MySqlConnection connection, string spName, bool includeReturnValueParameter)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                MySqlCommand cmd = new MySqlCommand(spName, connection);
                cmd.CommandType = CommandType.StoredProcedure;

                connection.Open();
                // 检索cmd指定的存储过程的参数信息,并填充到cmd的Parameters参数集中.   
                MySqlCommandBuilder.DeriveParameters(cmd);
                connection.Close();
                // 如果不包含返回值参数,将参数集中的每一个参数删除.   
                if (!includeReturnValueParameter)
                {
                    cmd.Parameters.RemoveAt(0);
                }

                // 创建参数数组   
                MySqlParameter[] discoveredParameters = new MySqlParameter[cmd.Parameters.Count];
                // 将cmd的Parameters参数集复制到discoveredParameters数组.   
                cmd.Parameters.CopyTo(discoveredParameters, 0);

                // 初始化参数值为 DBNull.Value.   
                foreach (MySqlParameter discoveredParameter in discoveredParameters)
                {
                    discoveredParameter.Value = DBNull.Value;
                }
                return discoveredParameters;
            }

            /// <summary>   
            /// MySqlParameter参数数组的深层拷贝.   
            /// </summary>   
            /// <param name="originalParameters">原始参数数组</param>   
            /// <returns>返回一个同样的参数数组</returns>   
            private static MySqlParameter[] CloneParameters(MySqlParameter[] originalParameters)
            {
                MySqlParameter[] clonedParameters = new MySqlParameter[originalParameters.Length];

                for (int i = 0, j = originalParameters.Length; i < j; i++)
                {
                    clonedParameters[i] = (MySqlParameter)((ICloneable)originalParameters[i]).Clone();
                }

                return clonedParameters;
            }

            #endregion 私有方法,字段,构造函数结束

            #region 缓存方法

            /// <summary>   
            /// 追加参数数组到缓存.   
            /// </summary>   
            /// <param name="connectionString">一个有效的数据库连接字符串</param>   
            /// <param name="commandText">存储过程名或SQL语句</param>   
            /// <param name="commandParameters">要缓存的参数数组</param>   
            public static void CacheParameterSet(string connectionString, string commandText, params MySqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

                string hashKey = connectionString + ":" + commandText;

                paramCache[hashKey] = commandParameters;
            }

            /// <summary>   
            /// 从缓存中获取参数数组.   
            /// </summary>   
            /// <param name="connectionString">一个有效的数据库连接字符</param>   
            /// <param name="commandText">存储过程名或SQL语句</param>   
            /// <returns>参数数组</returns>   
            public static MySqlParameter[] GetCachedParameterSet(string connectionString, string commandText)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

                string hashKey = connectionString + ":" + commandText;

                MySqlParameter[] cachedParameters = paramCache[hashKey] as MySqlParameter[];
                if (cachedParameters == null)
                {
                    return null;
                }
                else
                {
                    return CloneParameters(cachedParameters);
                }
            }

            #endregion 缓存方法结束

            #region 检索指定的存储过程的参数集

            /// <summary>   
            /// 返回指定的存储过程的参数集   
            /// </summary>   
            /// <remarks>   
            /// 这个方法将查询数据库,并将信息存储到缓存.   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符</param>   
            /// <param name="spName">存储过程名</param>   
            /// <returns>返回MySqlParameter参数数组</returns>   
            public static MySqlParameter[] GetSpParameterSet(string connectionString, string spName)
            {
                return GetSpParameterSet(connectionString, spName, false);
            }

            /// <summary>   
            /// 返回指定的存储过程的参数集   
            /// </summary>   
            /// <remarks>   
            /// 这个方法将查询数据库,并将信息存储到缓存.   
            /// </remarks>   
            /// <param name="connectionString">一个有效的数据库连接字符.</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="includeReturnValueParameter">是否包含返回值参数</param>   
            /// <returns>返回MySqlParameter参数数组</returns>   
            public static MySqlParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                using (MySqlConnection connection = new MySqlConnection(connectionString))
                {
                    return GetSpParameterSetInternal(connection, spName, includeReturnValueParameter);
                }
            }

            /// <summary>   
            /// [内部]返回指定的存储过程的参数集(使用连接对象).   
            /// </summary>   
            /// <remarks>   
            /// 这个方法将查询数据库,并将信息存储到缓存.   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接字符</param>   
            /// <param name="spName">存储过程名</param>   
            /// <returns>返回MySqlParameter参数数组</returns>   
            internal static MySqlParameter[] GetSpParameterSet(MySqlConnection connection, string spName)
            {
                return GetSpParameterSet(connection, spName, false);
            }

            /// <summary>   
            /// [内部]返回指定的存储过程的参数集(使用连接对象)   
            /// </summary>   
            /// <remarks>   
            /// 这个方法将查询数据库,并将信息存储到缓存.   
            /// </remarks>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="includeReturnValueParameter">   
            /// 是否包含返回值参数   
            /// </param>   
            /// <returns>返回MySqlParameter参数数组</returns>   
            internal static MySqlParameter[] GetSpParameterSet(MySqlConnection connection, string spName, bool includeReturnValueParameter)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                using (MySqlConnection clonedConnection = (MySqlConnection)((ICloneable)connection).Clone())
                {
                    return GetSpParameterSetInternal(clonedConnection, spName, includeReturnValueParameter);
                }
            }

            /// <summary>   
            /// [私有]返回指定的存储过程的参数集(使用连接对象)   
            /// </summary>   
            /// <param name="connection">一个有效的数据库连接对象</param>   
            /// <param name="spName">存储过程名</param>   
            /// <param name="includeReturnValueParameter">是否包含返回值参数</param>   
            /// <returns>返回MySqlParameter参数数组</returns>   
            private static MySqlParameter[] GetSpParameterSetInternal(MySqlConnection connection, string spName, bool includeReturnValueParameter)
            {
                if (connection == null) throw new ArgumentNullException("connection");
                if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

                string hashKey = connection.ConnectionString + ":" + spName + (includeReturnValueParameter ? ":include ReturnValue Parameter" : "");

                MySqlParameter[] cachedParameters;

                cachedParameters = paramCache[hashKey] as MySqlParameter[];
                if (cachedParameters == null)
                {
                    MySqlParameter[] spParameters = DiscoverSpParameterSet(connection, spName, includeReturnValueParameter);
                    paramCache[hashKey] = spParameters;
                    cachedParameters = spParameters;
                }

                return CloneParameters(cachedParameters);
            }

            #endregion
        }
    }
}